准备工具：IntelliJ IDEA
搭建目标：springboot+druid+mybatis_plus 并完成基本的增删改查功能
创建springboot项目
1、使用idea的new project选项创建一个springboot项目
file-->new -->project
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选择spring initializr，点击next
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填好项目一些重要的信息，继续点击next
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这里可以选择springboot版本和项目中需要的依赖；我这里使用的是2.2.4版本，而项目的依赖我习惯是在pom.xml中手动修改。就先选择个spring web吧。。继续点击next
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点击finish
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至此，一个springboot项目雏形搭建完毕~ 。 运行下试试，springboot和传统的ssm项目不同。内嵌了tomcat，所以不需要再配置了。这里直接找到main方法运行即可
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整合mybatis_plus
编写pom.xml 添加一些需要的依赖
以spring-boot-starter-parent 2.2.4.RELEASE为项目的父级依赖；
添加依赖mysql驱动5.1.38、druid连接池springboot版1.1.13、lombok、mybatis-plus3.3.1、spring-boot-starter-test
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>springboot_study</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot_study</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!--jdbc驱动，操作mysql数据库必备-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
<!--druid数据库连接池的springboot版本-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.13</version>
</dependency>
<!--lombok优化java写法的工具-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<scope>provided</scope>
</dependency>
<!--mybatis-plus的springboot版本-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.3.1</version>
</dependency>
<!--springboot的测试框架,里面有对junit4的依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!--springboot的web框架，引入它才能让java和web交互。可以使用@RestController注解了-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
创建几个包，注意这些包要和springboot的启动类平级，否则程序运行起来会报错，无法加载bean
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在刚才新建的config包内创建mybatis_plus的配置类MybatisPlusConfig.java
- 注意@MapperScan("com.springboot.study.demo1.mapper")注解内部的包路径指的就是mapper接口所在的包，这里可以使用*做通配符
package com.springboot.study.demo1.config;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.plugins.pagination.optimize.JsqlParserCountOptimize;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;
/**
*@description: mybatis_plus的配置类
*@author: yinkai
*@create: 2020/2/25 9:19
*/
@EnableTransactionManagement
@Configuration
@MapperScan("com.springboot.study.demo1.mapper")
public class MybatisPlusConfig {
@Bean
public PaginationInterceptor paginationInterceptor() {
PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
// 设置请求的页面大于最大页后操作， true调回到首页，false 继续请求 默认false
// paginationInterceptor.setOverflow(false);
// 设置最大单页限制数量，默认 500 条，-1 不受限制
// paginationInterceptor.setLimit(500);
// 开启 count 的 join 优化,只针对部分 left join
paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
return paginationInterceptor;
}
}
在entity包里添加实体类User.java
package com.springboot.study.demo1.entity;
import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;
import lombok.experimental.Accessors;
/**
*@description: User 实体类
*@author: yinkai
*@create: 2020/2/25 9:21
*/
@Data
@Accessors(chain = true)
public class User {
private Long id;
private String name;
private Integer age;
private String email;
@TableField(exist = false)
private Integer count;
}
在mapper包中添加UserMapper.java文件
- 接口上需要添加@Mapper注解
- 接口需要继承BaseMapper<User>，这个User泛型即是上面创建的实体类User
- mybatis_plus中可以不编写对应的xml文件
package com.springboot.study.demo1.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.springboot.study.demo1.entity.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
/**
*@description: UserMapper
*@author: yinkai
*@create: 2020/2/25 9:22
*/
@Mapper
public interface UserMapper extends BaseMapper<User> {
@Select("select * from user")
IPage<User> selectPageVo(Page<?> page);
}
在service包中创建UserService接口
- 注意service接口继承 IService<User>；这个User泛型即是上面创建的实体类User
- 该接口类里面包含了selectPage()分页接口
package com.springboot.study.demo1.service;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.IService;
import com.springboot.study.demo1.entity.User;
/**
*@description: UserService
*@author: yinkai
*@create: 2020/2/25 9:22
*/
public interface UserService extends IService<User> {
IPage<User> selectPage(Integer cPage, Integer pSize);
}
在service.impl包中创建UserService接口的实现类UserServiceImpl.java
- 实现类需要继承ServiceImpl<UserMapper, User> 类；UserMapper即是上面创建的mapper接口；这个User泛型即是上面创建的实体类User
- 实现UserService接口
- 注意添加@Service注解
package com.springboot.study.demo1.service.impl;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.springboot.study.demo1.entity.User;
import com.springboot.study.demo1.mapper.UserMapper;
import com.springboot.study.demo1.service.UserService;
import org.springframework.stereotype.Service;
/**
*@description: UserServiceImpl
*@author: yinkai
*@create: 2020/2/25 9:22
*/
@Service("userService")
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
@Override
public IPage<User> selectPage(Integer cPage, Integer pSize) {
Page<User> page = new Page<User>(cPage, pSize);
IPage<User> userIPage = this.getBaseMapper().selectPageVo(page);
return userIPage;
}
}
删除掉默认的application.properties配置文件，使用yml文件
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编写application.yml
- context-path，设置项目的访问根路径；访问项目时就要url加上test
- port，设置内嵌tomcat的端口号为 8080
server:
tomcat:
uri-encoding: UTF-8
max-threads: 1000
min-spare-threads: 30
port: 8080
connection-timeout: 5000ms
servlet:
context-path: /test
- mapper-locations，扫描加载指定路径下的xml文件
- typeAliasesPackage，扫描指定实体类包的全限定名
#mybatis-plus
mybatis-plus:
mapper-locations: classpath*:/mapper/**/*.xml
#实体扫描，多个package用逗号或者分号分隔
typeAliasesPackage: com.springboot.study.demo1.entity
- active， dev 指定加载的配置文件，分为三种环境dev|test|prod，所以还需要建立一个application-dev.yml文件方能完成配置
spring:
# 环境 dev|test|prod
profiles:
active: dev
servlet:
multipart:
max-file-size: 100MB
max-request-size: 100MB
enabled: true
mvc:
throw-exception-if-no-handler-found: true
全部的application.yml如下
# Tomcat
server:
tomcat:
uri-encoding: UTF-8
max-threads: 1000
min-spare-threads: 30
port: 8080
connection-timeout: 5000ms
servlet:
context-path: /test
spring:
# 环境 dev|test|prod
profiles:
active: dev
servlet:
multipart:
max-file-size: 100MB
max-request-size: 100MB
enabled: true
mvc:
throw-exception-if-no-handler-found: true
#mybatis-plus
mybatis-plus:
mapper-locations: classpath*:/mapper/**/*.xml
#实体扫描，多个package用逗号或者分号分隔
typeAliasesPackage: com.springboot.study.demo1.entity
global-config:
#数据库相关配置
db-config:
#主键类型 AUTO:"数据库ID自增", INPUT:"用户输入ID", ID_WORKER:"全局唯一ID (数字类型唯一ID)", UUID:"全局唯一ID UUID";
id-type: AUTO
#字段策略 IGNORED:"忽略判断",NOT_NULL:"非 NULL 判断"),NOT_EMPTY:"非空判断"
field-strategy: NOT_NULL
#驼峰下划线转换
column-underline: true
logic-delete-value: -1
logic-not-delete-value: 0
banner: false
#原生配置
configuration:
map-underscore-to-camel-case: true
cache-enabled: false
call-setters-on-nulls: true
jdbc-type-for-null: 'null'
编写application-dev.yml配置
这里主要是druid连接池的配置，因为本地环境、测试环境、正式环境的mysql访问ip 密码都不会相同。所以会有多种配置
spring:
datasource:
type: com.alibaba.druid.pool.DruidDataSource
druid:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/jdbcstudy?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false
username: root
password: yk123
initial-size: 10
max-active: 100
min-idle: 10
max-wait: 60000
pool-prepared-statements: true
max-pool-prepared-statement-per-connection-size: 20
time-between-eviction-runs-millis: 60000
min-evictable-idle-time-millis: 300000
test-while-idle: true
test-on-borrow: false
test-on-return: false
stat-view-servlet:
enabled: true
url-pattern: /druid/*
login-username: admin
login-password: admin
filter:
stat:
log-slow-sql: true
slow-sql-millis: 1000
merge-sql: false
wall:
config:
multi-statement-allow: true
在controller包下创建UserController.java文件
package com.controller;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.api.R;
import com.entity.User;
import com.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
*@description: user控制类
*@author: yinkai
*@create: 2020/2/25 9:21
*/
@RestController
@RequestMapping("/user")
public class UserController {
@Autowired
private UserService userService;
@RequestMapping("/list")
public R list(){
IPage<User> userIPage = userService.selectPage(1, 10);
return R.ok(userIPage);
}
}
数据准备
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
`name` varchar(30) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '姓名',
`age` int(11) NULL DEFAULT NULL COMMENT '年龄',
`email` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '邮箱',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 13 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES (1, '小羊', 31, 'abc1@mp.com');
INSERT INTO `user` VALUES (2, '小mao', 32, 'abc2@mp.com');
INSERT INTO `user` VALUES (3, '小gou', 3, 'abc3@mp.com');
INSERT INTO `user` VALUES (4, '小niu', 344, 'abc4@mp.com');
INSERT INTO `user` VALUES (5, '小ren', 213, 'abc5@mp.com');
INSERT INTO `user` VALUES (6, '小qi', 32, 'abc6@mp.com');
INSERT INTO `user` VALUES (7, '小che', 444, 'abc7@mp.com');
INSERT INTO `user` VALUES (8, '小chuang', 3213, 'abc8@mp.com');
INSERT INTO `user` VALUES (9, '小hong', 34, 'abc9@mp.com');
INSERT INTO `user` VALUES (10, '小lv', 55, 'abc10@mp.com');
INSERT INTO `user` VALUES (11, '小wang', 366, 'abc11@mp.com');
INSERT INTO `user` VALUES (12, '小qiang', 1, 'abc21@mp.com');
SET FOREIGN_KEY_CHECKS = 1;
全部文件创建文完毕，运行springboot。访问接口
http://localhost:8080/test/user/list
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项目运行ok~
添加增删改查接口
编写UserController.java文件；完成对User表的增删改查功能，这里就体现了mybatis_plus的开发效率了，普通的增删改查不需要动service和mapper。改了controller就ok了，功能实现一气呵成
package com.springboot.study.demo1.controller;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.api.R;
import com.springboot.study.demo1.entity.User;
import com.springboot.study.demo1.service.UserService;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/**
*@description: user控制类
*@author: yinkai
*@create: 2020/2/25 9:21
*/
@RestController
@RequestMapping("/user")
public class UserController {
@Resource
private UserService userService;
/**
* 分页查询
* @param cPage
* @param pSize
* @return R
*/
@RequestMapping("/list")
public R list(Integer cPage,Integer pSize){
IPage<User> userIPage = userService.selectPage(cPage, pSize);
return R.ok(userIPage);
}
/**
* 根据id查询
* @param id
* @return R
*/
@RequestMapping("/getById")
public R getById(Integer id){
User IPage = userService.getById(id);
return R.ok(IPage);
}
/**
* 根据id删除
* @param id
* @return R
*/
@RequestMapping("/deleteById")
public R deleteById(Integer id){
boolean b = userService.removeById(id);
return R.ok(b);
}
/**
* 根据id修改
* @param id
* @param name
* @param age
* @param email
* @return R
*/
@RequestMapping("/updateByid")
public R updateByid(Integer id,String name,Integer age,String email){
boolean b = userService.update(
new UpdateWrapper<User>().set("name",name).set("age",age).set("email",email).eq("id",id)
);
return R.ok(b);
}
@RequestMapping("/addUser")
public R addUser(String name,Integer age,String email){
boolean save = userService.save(new User().setAge(age).setName(name).setEmail(email));
return R.ok(save);
}
}
